Solar cell or photovoltaic device suffers conversion inefficiency; they are typically able to convert only a portion of the solar spectrum, the longer wavelength between 400 nm and 1100 nm for example, to electricity, and the shorter wavelength lower than 400 nm (higher energy portion) is wasted. To improve the conversion efficiency of the solar cell or the photovoltaic device, a number of schemes have been proposed in past decades. These schemes have attempted to make use of the solar spectrum more efficiently.
The mechanism of quantum cutting absorbs a high-energy photon and emits two low-energy photons. A quantum cutting phosphor (QC phosphor) based on the mechanism of quantum cutting could generate two low-energy photons corresponding to one incident high-energy photon, and the quantum efficiency is two. The development of near IR quantum cutting phosphor opens a new approach in achieving high efficiency of silicon-based solar cell by absorbing one photon in the UV part of the solar spectrum and emitting two photons near 1000 nm.